关键词: 呼吸窘迫综合征, 成人；肺通气；侧卧位通气；俯卧位通气；超声检查；治疗结果

Abstract: Background　The effectiveness of mechanical ventilation by position in patients with acute respiratory distress syndrome（ARDS） has been explored in some studies，but the therapeutic effect differences between lateral position ventilation （LPV） and prone position ventilation （PPV），and between patients with ARDS originating from pulmonary disease （ARDSp） and ARDS originating from extrapulmonary disease （ARDSexp） have not been clarified. Objective　To compare the therapeutic effects of LPV and PPV in patients with ARDSp and ARDSexp，and to explore their application strategy and value. Methods　85 patients with ARDS （including ARDSp and ARDSexp patients） who received treatment （without experience of changing ventilation position in this episode prior to this study） in the Intensive Care Unit，Affiliated Hospital of North Sichuan Medical College during September 2019 to May 2020 were enrolled，and divided into four groups for comparing LPV and PPV：ARDSp+ LPV group （n=21），ARDSexp+ LPV group （n=21），ARDSp+ PPV group （n=22） and ARDSexp+ PPV group （n=21）.Indices monitored before，and 0.5，1，and 2 hours after changing ventilation position were also collected，including：（1）baseline data such as age，sex，BMI，temperature，heart rate，and APACHEⅡ （2） arterial blood gas parameters：partial pressure of oxygen（PaO2），partial pressure of carbon dioxide （PCO2），arterial oxygen saturation（SaO2） and PaO2/FiO2 ratio；（3） respiratory mechanical parameters：peak airway pressure （Ppeak），rapid shallow breathing index （RSBI），plateau pressure （Pplat） and static pulmonary compliance （Cst）；（4） ICU sonography results：left ventricular ejection fraction （LVEF），inferior vena cava diameter （IVC-D），left ventricular derived cardiac output （CO），tricuspid annular plane systolic excursion （TAPSE），mitral annular plane systolic excursion （MAPSE），ratio of peak E-wave velocity/ peak e' velocity （E/e'），mean arterial pressure （MAP） and lung ultrasound （LUS） score. （5） cardiac biomarker：serum NT-proBNP；（6） prognosis：28-day mortality and incidence of complications. Results　PaO2/FiO2 was influenced significantly by the interaction effect of treatment time and ventilation position （P<0.05）. It was also impacted obviously by the main effect of treatment time（P<0.05），as well as by that of ventilation position （P<0.05）. SaO2 was affected notably by the interaction effect of treatment time and ventilation position（P<0.05）. It was also influenced considerably by the main effect of treatment time （P<0.05），as well as by that of ventilation position （P<0.05）. PaO2 was affected remarkably by the interaction effect of treatment time and ventilation position （P<0.05）. It was also affected greatly by the main effect of treatment time（P<0.05），and by that of ventilation position （P<0.05）. The PaO2/FiO2 and PaO2 in all groups were much better after changing the supine position ventilation（SPV） to LPV or PPV for 0.5，1 and 2 hours （P<0.05）. The PaO2/FiO2 and PaO2 at 0.5，1 and 2 hours after changing SPV to LPV were much higher in ARDSexp+ LPV group than in ARDSp+ LPV group （P<0.05）. The PaO2/FiO2 and PaO2 at 0.5，1 and 2 hours after changing SPV to PPV were much higher in ARDSexp+ PPV group than in ARDSp+ PPV group （P<0.05）. The PaO2/FiO2 and PaO2 at 0.5，1 and 2 hours after postural changes in ARDSexp+ PPV group were higher than those in ARDSexp+ LPV group （P<0.05）. The PaO2/FiO2 and PaO2 at 0.5，1 and 2 hours after postural changes in ARDSp+ PPV group were higher than those in ARDSp+ LPV group （P<0.05）. The SaO2 in all groups increased significantly after changing the SPV to LPV or PPV for 2 hours （P<0.05）. LVEF was influenced by the interaction effect of treatment time and ventilation position （P<0.05）. It was also impacted obviously by the main effect of treatment time（P<0.05），as well as by that of ventilation position（P<0.05）. The LVEF in all groups increased significantly after changing the SPV to LPV or PPV for 1 and 2 hours （P<0.05）. The mean LUS score was influenced significantly by the interaction effect of treatment time and ventilation position （P<0.05）. It was also impacted obviously by the main effect of treatment time（P<0.05），and by that of ventilation position （P<0.001）. The mean LUS score in all groups reduced significantly after changing the SPV to LPV or PPV for 1 and 2 hours （P<0.05）. The mean LUS score was negatively correlated with PaO2/FiO2 during SPV（r=-0.439，P<0.001）. And the correlation between them remained negative after SPV was changed to LPV or PPV for 1 （r=-0.348，P=0.001） and 2 hours（r=-0.327，P=0.002）. No obvious complications were found during the treatment. There was no significant difference in 28-day mortality among the four groups （χ2=1.333，P>0.05）. Conclusion　Changing ventilation posture rapidly and accurately according to patient condition for improving therapeutic effectiveness may be a future research hotspot in ARDS. ARDSexp patients gained more benefits from changing ventilation posture than ARDSp patients. Although PPV was slightly better than LPV in improving lung ventilation，LPV should be considered first when treating patients with complex conditions.

Key words: Respiratory distress syndrome, adult；Pulmonary ventilation；Lateral position ventilation；Prone position ventilation；Ultrasonography；Treatment outcome